KVM: s390: don't use current->thread.fpu.* when accessing registers

As the meaning of these variables and pointers seems to change more
frequently, let's directly access our save area, instead of going via
current->thread.

Right now, this is broken for set/get_fpu. They simply overwrite the
host registers, as the pointers to the current save area were turned
into the static host save area.

Cc: stable@vger.kernel.org # 4.7
Fixes: 3f6813b9a5 ("s390/fpu: allocate 'struct fpu' with the task_struct")
Reported-by: Hao QingFeng <haoqf@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
David Hildenbrand 2016-08-16 14:38:24 +02:00 committed by Christian Borntraeger
parent ba913e4f72
commit a7d4b8f256

View File

@ -2231,9 +2231,10 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
return -EINVAL;
current->thread.fpu.fpc = fpu->fpc;
if (MACHINE_HAS_VX)
convert_fp_to_vx(current->thread.fpu.vxrs, (freg_t *)fpu->fprs);
convert_fp_to_vx((__vector128 *) vcpu->run->s.regs.vrs,
(freg_t *) fpu->fprs);
else
memcpy(current->thread.fpu.fprs, &fpu->fprs, sizeof(fpu->fprs));
memcpy(vcpu->run->s.regs.fprs, &fpu->fprs, sizeof(fpu->fprs));
return 0;
}
@ -2242,9 +2243,10 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
/* make sure we have the latest values */
save_fpu_regs();
if (MACHINE_HAS_VX)
convert_vx_to_fp((freg_t *)fpu->fprs, current->thread.fpu.vxrs);
convert_vx_to_fp((freg_t *) fpu->fprs,
(__vector128 *) vcpu->run->s.regs.vrs);
else
memcpy(fpu->fprs, current->thread.fpu.fprs, sizeof(fpu->fprs));
memcpy(fpu->fprs, vcpu->run->s.regs.fprs, sizeof(fpu->fprs));
fpu->fpc = current->thread.fpu.fpc;
return 0;
}